Upgrade from SRH940s with better bass under $500?

Hey guys. Second post from a longtime forum dweller :P. I bought my SRH940s about a year ago and I really liked them. I just really found the bass lacking. Also I got pretty turned off by their poor sound isolation. I'm looking for definitely closed back headphones that can handle huge hip-hop bass, but hopefully with the same clarity as the SRH940s. I love me some hip-hop, but I listen to a lot of genres (classical, dance, dubstep, jazz) so I guess I want headphones that sound good with any genre. Maybe too tall a task! I've been considering the Denon D5000s (I found them on ebay for $500).